Mercury switch



MERCURY SW Filed Ja n 8 8 Patented Nov. 13, 1951' MERCURY SWITGH.

Raymond P. Matter-n, Minneapolis; Minn, as-

signor to Minneapolis--idnneyvizellv Regulator Company, Minneapolis,Minn.,.a-cornoration of Delaware Application January 8, 1948, SerialNb.1,126

(i-Claims. 1.

My invention relates toan electric switch of the type having a liquidcontact-circuit closer for controllingthe flow ofcurrent' therethrough,and more particularly to the mounting structurefor the circuit'cl'oser;

It is therefore an. object of this invention to provide an improvedconstruction and arrangement in a switch of this type.

Other objects and advantages will becomeapparent with the reading of thefollowing specification anddrawings wherein:

Figure 1 isa plan view ofthe-preferred-embod iment oi this'invention;

Figure. 2 is a side elevation view of theswitch shown in Figure 1; and

Figure 3' is a cross-sectional viewof the liquid contact circuit closerincluded in the preferred embodiment of'the-switch.

Figure-4 is a sectional view or the switch taken along linesi' i=ofFigure-l.

As is seenin the drawings, my invention is shown. applied to a switchincorporating a rotatable liquid contact circuit controller which iscommonly known as: a rotary metal mercury switch. Such a switch can: beseen in my Patent Numbers 2 2693745, dated October: 283 1941 and$342,354, dated Febr.uary:22, 1944; which are as.- signed' to; thesame:assignee as the present inveiie tion. The electricswitch. it generallydisclosed in Figures-l and 210i the drawing comprises aliq uid contact.circuit. controller i icpositioned1in= an insulated switch housing: i2.and: mounted; ferrotationv therein-,. to: provide a. manually: operatedwall switch-.ofrtl'ietoggletype,

The. liquid contact circuit controller, l;l,.0r rotary' metal mercuryswitch,v is composed: of: me.- tallic cup-like"; electrodes 1.3;. 1.4-.telescopically in.- terfitted; and. separated. by;- ceramic partition.or bafile. i5. which. has. an; aperture. Iii therethrough to permitcontact of. the mercury bodies; [1 separated bythebafiieandcomplete-thecircuittheree through. Aninsulating asbestoswasher Zilfurther separates electrodes I 3, l4 and aeglassseal or fillit between the electrode members, seals the.v insulating washer. 2.0andthe, ceramic in po..- sition. while adhering to. the. electrode.members to provide an airtight seal for. the container. Metal mercuryswitch H contains a hydrogen atmosphere. with the mercury fill" II, asis conventional in mercuryswitches. Indent 22in'el'ectrode 13 of thecircuit closer H isprovided in the manufacture of the switch for thepurpose of evacuatingand sealing the sameand is utili'zed herein, aswill-' be hereafter described; as a-meansof mounting the switch;

The switch housing i2 is a box like casing structure with a switchreceiving recess 28 open at thefi'ont. Thehousing 12 is made of aninsulating material, such as molded plastic, and is generallyrectangular with the exception of two extendingboss portions 23; 25"wherein the conductivemembers 25 2B are mounted to-the switch housing Ii. Switch housing it includes on its inner surface an inwardlyprojecting boss portion. 217- which is shaped on its inner surface toconform with the surface of electrode E4 of switch: Hi The boss 2*?"providesa fiat bearing surface engaging the fiat end of" switchelectrode I74 and acylindrical bearing surface engagmg? a cylindricalsurf-ace of electrode I4. These surfaceslbcate the switch H in thehousing [2. A. conductor 25: attached to boss portion 23 of switchcasing such as byscrew 36', is made of? a good electrical. conductivematerial and is bent to project into the recess 28- of switch housing:I12 with its free extremity curved to conform with and engage thecup-like electrode I4 of switch III; The conductor 25- isflexible andis: shaped to=engage the electrode It and bias the switch IJIL into.engagement with the. cylindrical bearing: surface: of boss 21: which iscurved to conform with electrode M of liquid contact circuit closer ll.Since the entire portion. of the cup -lihe electrodes; l3, M are made ofthe good electrical conductive material, electrical contact is made-byengagement of conductor ttwith electrode It; A conductor 25, attached atone extremity to: boss: portion 24* of switch housing I2 ina suitable.manner, such as by screw 33, extends into the recess 28 of switchhousing [2 and is bent to engage electrode 83- of circuit closer H.Theconductor 26.. is provided intermediate itsendswith. aprojecting knobportion 32 curved to, conform. to. and adapted. to. coact with theindent. 2.2. in. electrode i. switch ii. The free extremity 33 of theconductor 25 engages a surface. of. the. wall. of switch housing !2insuring definite positioning of circuit closer J l within switchhousing [2. Electrical contact is made through engagement of. knobportion 32 and in.- dent' 22' in. a ball and socket connectionwhichfurther provides. for pivoting of circuit. closer ii about. its axis andcentering of. the same, such that it is biased into engagement with theopposite wall of switch housing 32' and is held there for rotation byprojecting boss portion 21 and conductor 25 about its axis. The functionof conductor 2-6 is tobias the switch H in a direction normal to theoperation or bias of conductor 25- providing for a simple yet positivepositioning 3 of the switch with good electrical contact therethrough.

Cemented to circuit closer H is handle portion 34 which provides themeans of rotating circuit closer I I about its axis. A mounting strap orbracket 35 is provided to mount switch It! in the usual wall box. It isattached to switch housing 2 at lug portions 36 thereon and is providedwith opening 31 through which handle 34 extends. Bracket 35 alsocontains mounting holes 40 therein to facilitate mounting.

Switch I is operated by movement of handle 34 from an off to an onposition to establish an electrical circuit through the conductormembers and the switch I I mounted therebetween. The switch is centeredfor rotation about its axis by conductors 25, 2B and boss portion 21. Atthe same time a good electrical contact is established with theelectrodes of the switch which is not affected by rotation thereof. Theoutwardly extending boss portions 23, 24 of switch housing 12 arefabricated so that external wires, or connections, not shown, can easilybe connected to the conductors at mounting screws 3B, 3!. As is shown inFigure 2, movement of handle 34 rotates circuit closer II in such amanner that aperture H5 in ceramic bafile i5 is moved above or below thelevel of mercury in circuit closer H. In this manner contact is eithermade or broken between the two pools of mercury positioned on eitherside of baifie 15.

The mounting structure described above provides a simple and effectiveway of positively engaging a rotary type metal mercury switch to preventlost motion and to provide good electrical contact through the switch.This type of structure eliminates the necessity of biasing the switchand handle to predetermined operating positions since frictionalengagement of the electrodes of the switch with the conductors and theengaging portions of the switch housing maintain the switch in theposition desired.

In considering this invention it should be kept in mind that the presentdisclosure is intended to be illustrative only and the scope of theinvention is to be determined only by the appended claims.

I claim:

1. A switch comprising, a casing member having a switch receiving recessand a boss portion integral therewith projecting into said recess, arotatably operable mercury switch having two electrodes one of whichelectrode has a detent, a flexible connector member attached at oneextremity to said casing member and having a curved portion conformingto one electrode of said switch making electrical contact therewith,said connector member biasing said switch into engagement with said bossportion, a second flexible electrode secured at one extremity to saidcasing member and having a projecting knob near its opposite extremityadapted to coact with said detent in said switch electrode makingelectrical contact therewith, said second named connector member biasingsaid switch in the direction of said boss and said first named connectormember in a plane normal to the operation of said first named connector,said boss and said connector members cooperating to establish astationary axis of rotation for said switch prohibiting axial movementof said switch while permitting rotational movement about said axis, andmeans operatively connected to said switch for rotating the same aboutsaid stationary axis.

2. A device of the class described, in combination, a switch, a casingmember having a recess adapted to receive said switch, a boss integralwith said casing member extending into said recess with its inwardlyextending extremity adapted to conform to said switch, a flexible memberattached at one extremity to said casing and shaped to conform to andfrictionally engage said switch biasing it in a direction of engagementwith said boss, and a second flexible member attached at one extremityto said casing member and adapted to engage said switch biasing it in adirectionnormal to the direction of operation of said first namedflexible member, said boss and said flexible members cooperating toestablisha stationary axis of rotation for said switch while prohibitingaxial movement thereof but permitting rotation of said switch about saidstationary axis.

3. In a device of the class described, the combination of a switchcasing member having a switch receiving recess, a switch, a boss portionon said casing member adapted to engage said switch, a flexible membersecured to said casing and adapted to engage and bias said switch intoengagement with said boss portion of said casing member, and a secondflexible member secured to said casing and adapted to engage said switchbiasing the same in a direction normal to the operation of said firstnamed flexible member, said switch being adapted to be irictionallyengaged by said flexible members and slidably rotated about a stationaryaxis determined by said flexible members and said boss while being heldagainst axial movement.

4. In a, device of the class described, the combination of a casingmember having a switch receiving recess, a switch having conductorsthereon, a boss portion included in said casing member and adapted toengage said switch, a flexible member secured to said casing and adaptedto engage and bias said switch into engagement with said boss portion ofsaid casing member, and a second flexible member secured to said casingand adapted to engage said switch biasing the same in a direction normalto the operation of said first named flexible member, said first andsecond flexible members being made of electrically conductive materialand providing electrical connections to said switch conductors, saidboss portion and said flexible members cooperating to establish astationary axis of rotation for said switch permitting rotation thereonwhile prohibiting axial movement of said switch.

5. In a switch of the class described, the combination of an insulatedcasing membe having a switch receiving recess and a switch with aplurality of electrodes positioned therein, a boss portion integral withsaid casing member extending into said recess and adapted to be engagedby said switch, a flexible connector member of electrical conductivematerial secured at one extremity to said casin member and frictionallycontacting an electrode of said switch biasing said switch intoengagement with said boss portion, a second flexible connector member ofelectrical conductive material secured at one extremity to said casingmember and adapted to frictionally engage another electrode of saidswitch biasing said switch in a direction normal to the operation ofsaid first named connector member, said boss portion and aid flexibleconnector members defining with said switch a stationary axis ofrotation about which said switch is adapted tobe 5 rotated while beingmounted to prohibit axial movement thereof.

6. In a device of the class described, in combination, a casing memberhaving a switch receiving recess therein with an aperture leadingthereto, a boss portion integral with said casing member having asemicircular surface thereon projecting into said recess, a rotatablyoperative mercury switch having two cylindrically shaped electrodes oneelectrode of which has a detent therein, said switch being positionedwithin said recess of said casing member with one of the electrodesabutting said semicircular surface of said boss portion, a flexibleconnector member attached at one extremity to said casing member andhaving a curved portion conforming to and engaging said one of saidelectrodes of said switch remote from and diametrically opposite saidboss and making electrical contact therewith, said connector memberbiasing said switch into engagement with said boss, a second flexibleelectrode member secured at one extremity to said casing member andhaving a projecting knob near its opposite extremity adapted to engagethe detent in the other of said electrodes making electrical contacttherewith, said second connector member biasing said switch in thedirection of said boss and said first named connector member in a planenormal to the operation of said first named connector member, said bossand said connector members cooperating to establish a stationary axis ofrotation for said switch prohibiting axial movement thereof whilepermitting rotational movement of said switch about said stationaryaxis, and handle means of insulating material attached to said switchextending out of said recess in said switch casing through saidaperture.

RAYMOND P. MATTERN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,047,931 Brown July 14, 19362,101,093 Payne Dec. 7, 1937 2,142,107 Brown Jan. 3, 1939 2,142,154Sambleson Jan. 3, 1939 2,275,853 Hutt Mar. 10, 1942 2,365,444 BabencoDec. 19, 1944 FOREIGN PATENTS Number Country Date 466,257 Great BritainMay 25, 1937 520,357

Germany Mar. 10, 1931

